Most Of An Organism’s Dna Is Carried By Its _____.

chapter 8 and 11 bio

It produces four haploid cells and allows exchange of genetic material between homologous chromosomes.

Orientation of homologous pairs of chromosomes at metaphase I results in alternative arrangements that contribute to genetic variation in offspring. The orientation is called _____.

independent assortment

Crossing over is __________.

the exchange of corresponding portions of homologous chromosomes

Accidents can occur in meiosis wherein members of a chromosome pair fail to separate at anaphase. This is called _____.

nondisjunction

The function(s) of meiosis is/are _____.

reproduction (production of gametes)

Meiosis starts with _____ cells and produces _____ gametes.

diploid … haploid

Meiosis is typically accomplished in _____.

three steps. All of the chromosomes are duplicated in a diploid cell, and then there are two cell divisions to produce a total of four haploid gametes.

The _____ separate in meiosis I; the _____ separate in meiosis II.

homologous chromosomes … sister chromatids

Most of an organism’s DNA is carried by its _____.

chromosomes

Replication of chromosomal DNA occurs __________.

before a cell divides

With the exception of gametes, a human cell contains _____ chromosomes.

46

The cell cycle is a series of events that occur in which order?

G1, S, G2, mitosis, cytokinesis

Which of the following is the correct order for the four main stages of mitosis?

prophase, metaphase, anaphase, telophase

In sexually reproducing multicellular organisms, the main functions of mitosis are _____.

tissue repair/replacement of damaged cells, growth and development

Which events occur during prophase?

The nuclear envelope breaks down. Chromosomes condense and are attached to spindle fibers.

Cytokinesis _____.

finishes mitosis by dividing the cytoplasm and organelles of the original parent cell into two separate daughter cells

During _____, the cell carries out its normal functions and the chromosomes are thinly spread out throughout the nucleus.

interphase

Looking through a light microscope at a dividing cell, you see two separate groups of chromosomes on opposite ends of the cell. New nuclear envelopes are taking shape around each group. The chromosomes then begin to disappear as they unwind. You are witnessing _____.

telophase

A cancer cell __________.

does not respond to the signals that control cell division

Most human cancers are __________.

caused by an accumulation of mutations

Which of the following best describes cancer cells?

Controls governing cell division have been altered.

_____ is a carcinogen that promotes colon cancer.

fat

All your cells contain proto-oncogenes, which can change into cancer-causing genes. Why do cells possess such potential time bombs?

Proto-oncogenes are necessary for normal control of cell division.

The genes that malfunction and cause a cell to become cancerous usually __________.

regulate cell division

What name is given to a gene that causes cancer?

oncogene

Inheritance of certain genes increases the risk of getting certain cancers; thus, it can be said that ______.